Mechanism for liquefying air and separating same into oxygen and nitrogen.



J. P. PLACE, m) SEPARATING SAME INTO APPIJIUATION FILED KOV.17, 19 03. 978,935.

MECHANISM r011 LIQUBFYING AIR A OXYGEN AND NITROGEN.

Patented Dec. 20, 1910.-

2 BHBETS-SHEET 1.

J. F. PLACE. MECHANISM FOR LIQUEFYING AIR AND SEPARATING SAME INTO OXYGEN AND NITROGEN.

APPLICATION FILED NOV.17,'1903. 978,935..

Patented Dec.20,19 10.

2 SHEETS-SHEET 2.

[ll/l Ill/f Ill/l/l/I war - UNITED STATES OFFICE.

JAMES 2*. PLACE.

OE GLEN RIDGE, NEW JERSEY, ASSIGNOB TQ AMERICAN AIR LIQUE- IEYING 00., A CORPORATION OF NEW YORK.

izfuoiumsm son moonrrme am am) s sruim'rnm sum m'ro O'XYGEN'AND mrnoemr.

Specification oiLetterl Intent. Patnted Dec, 20, 1910,

Application filed November 17, 1903. Serial No. 181,498;

To all uflwm it may concern- Be it. known that I. James F. Prison s. cmzen of the United States, and a resident of Glen Ridw, in the county of Essex and State I of which the following is a specification.

My invention relates to im rovements in apparatus or ltIt-(fllttlllSl'll for iquefiving atmospheric an', and also for separating such liqnld air into its constituent gases, oxygen;

and nitrogen. or commercial commercial nitrogen.

The object of my m'vent oxygen and ion is to reduce the cost ofthe lOtllKtlOll oftliquidair, and also:

to reduce t to cost of separating such liquid air into such commercial gases, and to make oration of such eoinmelclal a continuousoperation In order that those skilled in the art ma understand and make use of my invention,

will describe itb ing drawings, in which."-'

' Figure l is'a view in vertical section of practically the complete apparatus. F ig. 2

' vacuum.

is a view partly in vertical section, and on a larger scale, of the liquid air vaporizing was set, in part..-and of the oxygen vaporizing vessel, and liquid air reservoir, showing the automatic valves for filling the oxygen tank from the liquid air vaporizing vessel, after the nitrogen liquid has been separated from the liquid airby fractional distillation; and

' for automatically discharging the liquid air from the reservoir, and re-eharging the liquid air vaporizing vessel. Fig. 3 is a trans versesectional view of the expansion engine cylinder on the.line .r a: of Fig. 1, not showing; piston.

Similar reference marks refer to similar parts throughout the several drawings.

Thenmneral 1 presents unsuitable iuclosure or case, which incloses the various parts preferably in a vacuum space 2; this is for the pmpose ofinsulating such parts from the normal heat of the atmosphere, 2' being an air tight. covering to maintain said At. 3 in Fig. 1, show a. recipl'oc-atim airexpansion engine. This engine should be provided with suitahle-cut-otf valves, as at 4 v the aid of the accompanyand 4:, and also with suitable exhaust valves 5 and 5,all operated by suitable valve ear. In. combination with this engine I ave a'counter-current heatinterchanger, which comprises one high-pressure incom ng conduit, or feed pipe 7 (which sup lies the engine with live air, and. whici is fed from an outside compressor, orsource of compressed air supply which has had the heat of compression and moisture removed therefrom by the-mechanism shown in my U. S. Patent N 711,525, or some'other suitable and effective means), and two low-pressure outgoing conduits or'..pipes, 8 and 9, which carry-outside the apparatus, one (9) the rich nitrogen-and the other (8) the rich 70 sire.-ts ss mliislilw's s d m the hq'uid 'an' "1n and by the apparatus as hereinafter described. he pipes or conduitg comprisiiwthis intcrchanger, should be "tea fa'liliength and located Dra -ea in longitudinal juxtaposition with each other; the referred, construction is shmm, one tube insie'o'f another. :andj thesejtwo inclosed by a tliird.-the whole'thoroughly insulated :fimnthe lueat'fofi-its environments by the vacuum space 2,and"the dead air space filled with packings. 10 of 'rel'ativclv low heat-coir ductivity, preferably inclosed or surrounded by the outer protecting case 11.

At 12 I show an exhaust chamber. which receives the expanded cold exhaust. air-from the engine as delivered from the exhaust .-valves 5 and 5. The exhaust chamber is connected with and delivers to the condens- -n ig conduit: or pipe-13, which is preferably in form ofa helical coil and has an extension or continuation 13'. and at its delivery end is provided with a pressnrereleasing. .or. hock valve 14.

At; 15 I have a liquid air onnitrogcn vaporizing vessel or receptacle, in which is lo cated the helical condensing coil 13, said vaporizing vessel having preferably a "downwardlv projectin part 15', of about'oneuid air as it:- condenses from the cold exhaust 50 which is ope air in thezpipes 13 or 13? and is delivered through the valve 14. This reservoir is preferably made of somewhat larger capacity than the liquid air vn orizing vessel 15; and

it is connected with t e vaporizing vessel by atube 18 which tube is open at its delivcry or upper end to the upper part inside of the vessel 15, so that any liquid air in the vessel 15 cannot run down the tube; and the o lower end of this tube (18) is extended downwardly as shown, into the reservoir 17,

at 18' to near the bottom of said reservoir,

so that no gas can pass up the tube so lon" as the liquid air therein is sufficient to sea 5 or cover thelower end'or mouth of the tube.

At 19 is shown a branch pipe connectin the upper part inside. the reservoir 17 wit 1 the tube 18 (outside the reservoir) throu h the valve 20, the operation of which will 0 20 explained farther on.

At 21 I show what I call-my liquid air overflow i for it serves as an outlet from 'the to o the liquid air vaporizing vessel 15,

and a lows any overflow or surplus of liquid air which may be delivered to said vaporizvessel .to passinto the pipe 21, from f iv ch it ma be drawn off through the outside delivery-cock22; th sioverflow pipe is preferably made in form of a helical coil so as'to' give it considerable length,

and emb -netmly anke it of larger holding eapacity, b1it"pre veii't, the heat from be-. -ing conducted from outside-the apparatus into the vessel 15.

The piston rod 23 of the expansion engine (3) is connected'with a connecting rod and Qerank, otitsideJthhapparatus, in the usual way andthe power at the engine may be infllielping topornp essthe-air usedin 40, running the enging jor tilized in any other manner. The'e!i 1 gfixed'to'the frame 24, and by the use of.

the, long sleeve 25 arouud-the piston rod, andof the strengthening ribs 26,'the sectional area ofconducting material for heat to pass in to the apparatus from its environ'mentsis reduced to the minimum The li uid oxygen va orizing tank 16 is connect with t 1e liqui air vaporizin vessel 15, through the valve 27,

rated automatically as hereinafter described. This oxygen vaporizin tank (16) .h'as an oxygen vapor pipe 8' whic 1 asses around the ei'i'gine and is connected. with and delirers,-prefierably, to the inner low-pressure pi e 8 of the counter=current intercl'mnger. 'l he liquid air, distilling vessel (15) is" connected with'orjs open to the passage 28 around the engine, preferably as shown in Figs. 1 and 3, which passage delivers to the outer low-pressure conduit 9 of the interchanger; It will thus be seen that all the cold gases or va mrs distilled, from the liquid air charge in t e liquid air V2L|'IO1- .izing vessel 15, as well as all the oxygen 5 gases or cold vapors from the. liquid gas off the rod charge in the oxygen vaporizing tank 16, are passed out first around the engine, and then through the inter-changer in a countercurrent to the incoming compressed air'supplied to the engine through the hi h-pressure or middle annular conduit 7 o the inter-changer; in this way the normal heat of the compressed air in the so )ly pipe 7 is absorbed to the outgoing cold commercial nitrogen in conduit 9 and to the outgoing cold commercial oxygen in pipe 8, so that the initial temperature of the compressed air supplied to the engine is practically at the temperature of liquefaction, or so low that a considerable portion becomes li uefied as it is expanded and the heat ofsuc expanded an'is converted into work in the engine, and

such liquid air is delivered to the exhaust chamber 12, and thence passes down by gravity into the coils 13 and 13" and out through the pressure-releasing valve 14 into the reservoir 17. i

Valve 27 is operated by a float 30 (Fig. 2), which slips up and down on the rod 31 fixed to the valve but is prevented from getting by the cross bar 31'. At 32 I have a socket or casin to hold the valve 27 in place, and connecte with this is'the'tube from or vaporized liquid rich in ox gen,

cannot pass into the vessel 15 throng] the tube 34 but. must pass up into the pipe 8'. The -valvc 20 in'the rcservoir.17 is also antomatically operated; whenevcr the reservoir (17 is full of liquid. the float 36 which slides up and down on the valve rod 37, presses the valve to its sent; this (muses a pressure to generate in the reservoir. and the valve (20) is held t9 its seat until all the liquidis forced lip-through the pipes 18' and 18. As the liquid air level falls in the reservoir the float- (36) falls alsrmmd \vlu'n practically all the liquid is out. the (l ml (:16) ongages the lu, 38. and pulls the valve open; its own weight keeps it. 01W while the reservoir is being filled.

l am aware that attempts have been made to separate atmospln-rir air into its coir '10 cessive charges of liquid air are distilled,

"1a isentirely removed or delivered by itself from (br what is known as commercial oxyfooted by utilizing the latent heat of con-,

- condenser, and causing such heatto be taken so -up-'as the latent heat of vaporization of the pressure outgoing pipes.

stituent gascs;-hut such attempts have been usually confined to partially separating one gasfrom the other gas, while both are in the gaseous state, or else partially. separat ng 15 the gases during a continuous distillation anda continuous condensati0nthe vaporiiationof nitrogen and of oxygen going on both at the same time. In my apparatus, as preferably constructed, separate and sucseparately, distinct as to time and quantity; and when the nitrogen of each charge is nearly distilled, the remaining liquid (which is practically liquid oxygen) of such charge ,autbmatically into another and separate disti "iglrec'eptacle, where it is vaporized by itself-and e nearly pure oxygen gas thereg elp), is conducted into a separate conduit. v. e vaporization of the nitrogen-from the ,liquid aircharge in the first nstance, and of-the liquid oxygenor remainder. of the charge in the second instance, are both cf- 'dehsation' of expanded air (but air at a higher pressure than. the liquid charges) in 'a submerged condensing conduit or surface liquid air or liquid oxygen charges succcssively, thereby subjecting these liquid h charges successively to fractional distilla- 'tio The. heat}of-j .theincoming compressed 85. air 1s-absorbed .by the outgoing cold vapors (both nitrogen and oxygen) by the wellknown Siemens heat interchanger, in this case such interchang'er being made with one incoming high-pressure pipe and two low- Ordinarily an initialvcharge of liquid air may be provided in the distilling vessel 15, by assing it through the conduit 9; by use. of tlie expansion engine; however,.the appa- 4'5- rat-usmay be made to'produce its own ini- .tial charges of liquid air and also to counteract any losses which may result from imperfect insulation, and to recover a good part of the power required to compress the 60 air used. This engine is practically an airliquefying engine, for I locate it between the interchanger and the liquid airvaporizing vessel (15), so that the engine takes the comlpressed air from the intert ahanger and exausts into the condenser or'suhmerged condensing conduit. which is located in or passes through both the successive liquid air charges in the liquid air vaporizing vessel (I5) and the successive liquid oxygen charges in the liquid oxygen vaporizing-reccpt-acle.:(16). In this way the compressed .air in the high-pressure conduit of the interchanger is practically cooled to the liqucfy-. ing point before being expanded and made 55 to do work in the engine, which feature inl surplus as produced, so that ,a. uniform supplied to the annular conduit- '(7) outsures liquefaction of the n'mxinun-n amount in the engine; and the loss of. heat converted into work cools the unliqucfied remainder to the point of liquefaction'before being subjected to the cooling action of the liquid charges.

In this class of machines for the separation of the gases by fractional distillation. any heat received by the liquid air or liquid oxygen charges from any other source than the latent heat of condensation of the compressed air supplied to the apparatus will cause a gradual diminution in quantity of the liquid air charge, and a running down ofthe machine. Cooling the compressed air before it enters the interchanger. as has been attempted in some cases, will not prevent this; but liquefaction of a portion ofthe compressed air, by conversion ofits heat into external work by the engine, is a clear. gain, and will effectually counteract such a result. In fact, the operation, with my apparatus as herein shown, will -.be continuous, and with ordinarily good insulation from outside heat a surplus of the 90 liquid air will be produced over and above the amount evaporated in the va orizing vessels. Provision-is made, as wil be no ticed, for withdrawing from the system such charge will at all times be delivered to the vaporizing vessel (15) and thus successively uniform charges of liquid oxygen will he delivered to the oxygenv vaporizingfaiik (16) during theoperation. I

The operation of the apparatusfis as follows: Compressed air from some outside source from which the moisture jand the heat ofcompression have been removed, is

side the apparatus (see Fig. 1). This passes down through the heat interchanger to the cut-oil. valve chamber (40) of the engine and is delivered to the engine through the cut-off valves 4 and 4', and starts the engine, which is made to .do some outside work; asthe air is expanded in the engine, its ti'unpcraturc. falls according to the amount of work done, and is then delivered from the exhaust chamber 12 to the condenser 13 and 13", and passes thence tothe reservoir 17 through the valve 14, which. is set to open at. a trifle less pressure than that of the exhaust or expand- 0 air from the engine; thence it passes thro'iigh the valve 20,and pipe 18 to the liquid air vaporizing vessel 15-a'nd into'the passage 28 around the engine, which connects with the outgoing outer conduit 9 of the interchanger. This expanded air being about 200 degrees colder than the tirstin take of incoming compressed air in the conduit 7, quickly absorbs the heat from such compressed air, so that,the next following charges-delivered to the engine are soon so I cold that the temperature of the expanded 130 passes. in? through the passage 28,2 Figi-a charges in the engine fall below the condenl sation point, and are .partially liquefied. This liquefied air drops by gravity from the exhaust chamber (12) 'down" through the through the ressure-releasing valve H with the expande exhaust air which has not become liquefied, into the reservoir 17. As the engine continues torun', this reservoir (17) becomes filled with liquid air. and when it is full the float 36 engages the valve 20 and closes it; pressure quickly generates in the top of the reservoir 17' by vaporization of the liquid air -and by passage of vapor throu h the pipe 14' from the release valve 14,- wliich pressure holds the ventvalve 20.

tightly to its seat, while the'liquid air charge is forced up the'siphoxr tube 18.and 18 into the liquid air vaporizin vessel 15; The float 36 falls with the leve of the liquid, and presses the lug 38, and pulls open the vent- ,valve 20, when-ithe. pressum jsiareleiised bye:

'1 passage of the vapor through valve m into:

vessel 15. The condensing conduit 13 being now surrounded b or submerged in. the liquid'air charge, -t ie'latentheat of. the unliqu'efied butcold expanded exhaust air in the condenser (being under a-suitable terminal pressure)' -isiabsorbed.by and roduces fractional distillatiomof the liquh air -in vessel 1:3, and said exhaust exi n. pe s e.tt "y liq po'ri 'the'*-nitrdgnsevaporati (thus coolingand insulating the engine cylinder).into the outerainterehanger conduit (9), and" when about ,four-fifths of the charge has thus vaporized, or most of .thenitmgen has evaporated, the 'fioati iitl, F ig. 2, falls away from the cross-'jaarstllfe and the valve 27 (being released from any pressure in the tube 33) falls down by gravity in the socket or (use 32, and the whole remainder of the charge (now commercial liquid oxycn) in the vessel 15 runsfldown into the iquid ox 'gen vaporizing rcee tacle 16.-'the opening 34: then eing closed-f ythc float 30. The engine continuing to run, the cold exhaust air under the terminal pressure-in the condensing conduit 13, unliquefied, 'now pas es into the submerged coil 13'. and gives up its latent heat of condensation to theliquid oxygen, which Ina-outing va 'iorized passes ofii up through the pipe 8' into the outgoing pipe 8 of the .1ntere] anger;.-the liquid air, vaporizing vessel 15-is-then re charged from the reservoir 17, and the 0p oration is repeated automaticallv-the commen-la] oxygen gas being collected from pipeS. outside. and the nitrogen from pipe 9. outside.

liy my apparatus a very large portion of .tbe heat of the compressed air used for i l condensing conduits, 13, 13', and passes i siderable portion of the air is liquefied in gether by being transformed into work outside the apparatus; and thus there is that much less heat to be absorbed by the cold vapors (lQI'lVGdfl'OllllllO charges of liquid being vaporized or distilled. Besides, a conthe eugine by reason of its latent heat being converted 1nto work, and all ofthe expanded 4 exhaust air from the-engine is cooled to the ccted to the direct cooling action of the liquid charges there remains only the latent produce total liquefaction. Thus the fractrom the-cold expanded exhaust air, and this expanded air being at all times less in 'ized ifth'e insulation from outside heat is perfect, there will be a constant accumulaamount liquefied in the engine. By regulating, or adjusting the cut-,ofi

c'ut-otfmay be given, and thus a higher or lowemlfiefininahprwsure of the exhaust expanded... air; ,glelrvaned to the .oondenser be ;obtained; in thistway -jalso a greater or less amount of the expanding charges may be liquefied in the. engine and delivered with the unliuefied expan' ed air to the conengi 'efladjustment'of'thecut- E should to insure a. suitable of cou'densa'tionin the engine cylinder.

,ox gen'vessel 16, by which through the valve 43 the -'li'quid oaiygen, or liquid rich in oxygen, can be drawn off if desired before is allowed to vaporize; or the valve 43' may benset so that as fast as the liquid is dumped into vesel 16 from the residue in vessel '15 by the automatic valve 27, it may be collected from the outside pipe 44 in any suitable insulated receptacle, such for in stance as that. shown in my U. S. Patent 707,634. In this way the liquid commercial oxygen may be-put into air tight tanks, or dru1ns, and as it absorbs heat and becomes of the tennwratnre' of-its environments, it will vaporize into oxygen gas under pressure.

- Byregulating the cut-oil valve gear of the expansion engine 3, the temperature and puss-are of the. exhaust products. delivered 13 and 13'. may be so regulated that partial or fractional condensation may be secured the vessel 17 througlrvalve 14 (see Fig. 2.)espe -ially when the liquid commercial oxygen .-is drawn from the vessel 16 through pipe 4? ntltl the valve 43, instead of being liquefaction and separation disappears altopoint of liquefaction, so that as it is subheat to be absorbed or taken up in order to tional distillation of -t.he liquid charges is producedby the-latent heat'only derived I amount than the liquid charges to be vapor-.

gtio'n of-thttaliquidiicharges equivalent to the valve-gear ofthe engine, an earlier er later in ressionpf the .air' usedjn.

terminal. pressure and therequired amount At 42 I-have a; discharge pipe' from the to the chamber 12 and condensing conduits of the expanded air therein as delivered to 125 vaporized in said vessel and passed out 130 I initial charge of or commercial nitrogen .oxjvfjcn gas. In this way vserve the requirements through pipe 8 and the interchanger as a liquid rich in oxygen may be delivered to re ervoir 17 instead of liquid air, all the time; and naturall v. after va orization in vessel 15 of a portion of the c arge therein, a liquid richer in oxygen will be left as the residue. in ms sel l5, and delivered to the tank 16, and either vaporized therein or drawn off if desired through pipe 42 and valve 43.

Byproviding the apparatus with an liquid air, then a much lower pressure may be used in the engine, or only sufficient to make up for losses due to imperfect insulation.

Wherever the term commercial oxygen is used herein or in the claims, it means and comprehends in either case-a gas having oxygen or nitrogen in greater percentage or'proportion than found in the atmosphere at normal condition. i

,I donot confine myself to the particular construction shown of either the interchanger or the case, nor of the-vaporizing vessels and reservoir, nor of theiexpansion engine and its parts, nor of the condensing conduit or condenser, nor as to the automatic devices" and .and'suchsuitable construction, so as to'\best in order to secure the results sought to be obtained as herein set forth.

I am aware that the separation of air into its constituents nitrogen and oxygen by the =incoming supply fed to the engine by the fractional distillation; of liquid air, is not new; and I am also. aware that the liquefaction of air by gxpanding the same against resistance in an air engine, and cooling the exhaust therefrom, is in theory not new. But the cooling of compressed air supplied to an en 'ne, by the products of distillation of liqui' air, and the liquefaction of the expanded exhaust air from an engine by causingheat. to pass therefrom to liquid air-or 1 the evaporation of liquid air by heat derived from the expanded exhaust air of higher pressure from an englnc-are I believe new and original with, me; and, therefore, such devices and n'iechanism' as herein shown, or any similar devices for utilizing these novel functions herein described, are new and original with Inc. I am also aware that the distillation of separate charges of liquid air inter-mittcntly. is not new in theory; but the distillation intermittently of separate charges of liquid air by the devices and in the manner and for the purposes herein/shown, is new; and the distillation of said separate charges of liquid air intermitten'cly and automatically is new. And

the evaporation of thc'residue of separate air, after partial fractional 4 charges of liquid other parts. All such- [fartsshould be of: such suitable materialseparate and intermittentcharges of either liquid air, or liquid i'iitrogcn or liquid oxygen, by heat derived from the expanded air of higher pressure exhausted from an air ex: pansion exigine-whichis supplied with and operated ,by compressed air cooled before expansion in said engine by the cold gaseous products'of said evaporation. So also, so far as I know, it is'new and original with me, to arrange devices to draw otf and utilize for purposes outside the apparatus. the surplus liquid air produced therein, and the surplus liquid oxygen, or products of distillation of liquid air, therefrom, while in A liquid form. Therefore the devices and combinations herein shown and. described produce valuable results not heretofore. attained, and are new' and useful. improvements.

Having thus described my invention what I claim as new and original anddesire to secure by Letters Patent, is

1. The combination of an air-1i uefying reciprocating expansion engine with a liquid-a-ir vaporizing vessel, means for automatically supplying-said vessel with intermittent charges of liquid air, and means for I liquefying the exhaust air from said engine by the fractional distillation of.said auto matically delivered intermittent charges of liquid air in said vessel; and a receiver for said liquefied exhaust air, arranged to maintain saidexhau'st air in heat-interchanging relation with the intermittent charges, of liquid gir. j

2. The combination of an air-1i uefying reciprocating expansion engine wit a li'quid-air vaporizing vessel, means for automatically .supplyin said vessel with intermittent charges ofgiquid air and for lique fying theexhaust air from said on ine by the fractional distillation of saitf automatically delivered intermittent liquid-air charges; a receiver for the liquefied air ar- I ranged to maintain said exhaust air in heat- 1'15 interchanging relation with the intermittent charges of liquefied air, and means for cooling the compressed air supplied to said engine by the products of sai distillation.

3. In an apparatus for liquefying'air and separating the same, the combination of a liquid-air evaporating vessel, with a reciprocating air-expanding engine, having an exhaust" conduit within said evaporating vessel and means for automatically supplying said vessel with intermittent charges of liquid air of less pressure than the expanded air in said exhaust conduit.

4. Tu an apparatus for liquefying air and separating the same into its constituent gases, the combination of a liquid-air evaporating vessel with a reciprocating air-expanding engine ha ring an exhaust.- condn-ibi within said evaporating yessel, and means for automatically supplying said vessel wit-11 intermittent, charges of liquid air previously aforesaid in said exhaust condu it.

The combination of a l0v-'- p'ressure liquid-xii r evaporating vcs el, wit-h a reciprocatingairexpan ling engine, means for ant'ou atically evaporating by fractional distillation intermittent charges of low-pres- :ure liquid air in said yessel by heat derived from the exhaiist air of higher pressure 1.5

from said engine during the process of liquefaction thereof, and means for. automati- .ca]1y delivering intermittent charges to said vcsqel. of ImV-pressnre liquid air previously liquefied as the exhaust air as aforesaid.

Signed at New York, in the county of New York'and State ofXew York, this 16th-- .day of May A. D. 1903. 1

J AMES 1-. PLACE. Witnesses:

CLARENCE PLACE: J.Y F. 'DU' B015.

from said engine 20 

